Surface-unit terminal



F. W. CUFFE SURFACE UNIT TERMINAL July 9, 1929.

Filed July 19. 1928 Zlwvemtor 145 L' 1117' E Patented July 9, 1929.

UNITED STATES PATENT OFFICE.

FREDERICK WILLIAM CUFFE, OF WAYNESBORO, VIRGINIA, ASSIGNOR TO THE W. J.LOTI-I STOVE COMPANY, OF WAYNESBORO, VIRGINIA.

SURFACE-UNIT TERMINAL.

Application filed July 19,

This invention relates to electric stove terminals and more particularlyto terminals used in connection with flatsurface units.

The principal object of this invention is to provide a terminal whichwill insure a cooling contact between the copper leads and resistancewire.

Another object is to prevent the annealing of the terminal and thecontact wires which occurs so frequently at the present time in electricheating units.

Still another object is to provide a rigid construction which isessential to prevent a shorting of the current and at the same time toprevent destruction of the terminal.

1n order to successfully solve the problems stated, it is necessary tohave the terminals remote froln the source of heat, allow the terminalsto be in free circulation of air, and radiate as far as possible an heatwhich may travel down to the terminals.

The structure by which I have solved the particular problems isdescribed and shown in the accompanying specification and drawings.

In the drawing:

Figure 1 is a. top plan of the surface unit;

Figure 2 is a bottom plan of the surface unit shown in Figure 1;

Figure 3 is a section taken on line 33 of Figure 1;

Figure 4 is a fragmentar section taken on line 44 of Figure 3; and

Figure 5 is a bottom perspective of the surface unit.

Referring to the drawing:

Numeral 1 designates a surface unit including the resistance wires 2which extend at their free ends 3 through openings 4 in the surface unit1 through refractory tubes 5 to a terminal 6 which extends parallel tothe refractory tube or tubes 5. A threaded nut 7 is placed above andbelow the free end or ends 3 of the resistance wires 2 with a heatradiating fin in the form of a metal washer 8 placed between thethreaded nuts 7. A threaded nut 7 holds the terminal 6 snug against thesurface unit 1, through which the terminal passes. A wing nut 9 isthreaded upon the terminal 6 and holds the whole in place. A lead wire10 is connected to the terminal 6 below the free ends 3 of theresistance wire 2 but spaced from the same by nut 7. Below the surfaceunit 1, as shown in Figures 2 and 3, is a pan 11 with openings 1928.Serial N0. 294,033.

12 to allow for the escape of any drippings which may seep through theopening 13 in the surface unit 1. The primary purpose of the pan 11 isto act as areflecting surface, thus breaking the downward flow of heatfrom the resistance coil and consequently preventing as far as possibleheating the terminals and points of contact by radiation. It is truethat when the pan becomes heated it will in turn radiate heat, but theheat thus thrown off will be much less than if its radiation was notinterrupted by the pan. Another advantage of the pan 11 is that it actsas a mechanical support for the surface unit 1, which is usually made ofporcelain or other refractory material. By extending the pan, the wholediameter of the surface unit, there is much less danger of refractorymaterial cracking or breaking.

By continuing the free ends 3 of the resistance wire 2 throughrefractory tubes 5 parallel to the terminal 6, the wire is given achance to cool by means of radiation, and at the same time, the point ofcontact is spaced from the source of heat.

By extending the terminal 6 parallel to the refractory tubes 5, a rigidconstruction is obtained which is highly desirable. With thisconstruction, the annealing of the wires and terminal is done away withand at the same time, a construction of the greatest simplicity andefficiency is presented to the user. The use of the flat metal washer asa heat radiating fin will assist in materially discharging any heatwhich may travel down the terminal.

Having described my invention, I do not limit myself to the exactconstruction shown and described herein, but claim any equivalentstructure which may come within the breadth of my invention.

Having described my. invention what I claim is:

1. A heating unit comprising a plate having openings therein, resistancecoils mounted on said plate, the coils having free ends eX- tending fromsaid plate through said openings, a refractory tube surrounding eachfree end and extending substantially below said plate, a terminalextending from said plate parallel to said refractory tubes, and meansfor securing said free end of the resistance coil to said terminal.

2. A plate of refractory material having an electrical heating coilthereon, a refractory tube extending substantially perpendicularly fromsaid refractory plate, a metallic contact element extendingsubstantially from said refractory plate and adjacent to said refractorytube, and means on said metallic contact element for clamping to saidelement the ends of said coil projecting from said tubes.

3. A plate of refractory material having an electrical heating coilthereon, a reflection plate secured to the bottom of said plate ofrefractory material, a refractory tube extending substantiallyperpendicularly from said refractory plate, a metallic contact elementextending substantially from said refractory plate and adjacent to saidrefractory tube, and means on said metallic contact element for clampingto said element the ends of said coil projecting from said tubes.

4. A plate of refractory material having an electrical heating coilthereon, a refractory tube extending substantially perpendicularly fromsaid refractory plate, a metallic contact element extending from theupper side through said refractory plate substantially perpendicularlyto said plate and adjacent to said refractory tube and means on saidmetallic contact element for clamping to said element the ends of saidcoil projecting from said tubes. v

5. A plate of refractory material having an electrical heating coilthereon, a refractory tube extending substantially below said refractoryplate, a metallic contact element extending substantially below saidrefractory plate and adjacent to said refractory tube, heat radiatingfins extending from said metallic contact element and means on saidmetallic contact element below said heat radiating fins for clamping tosaid element ends of said coil projecting from said tubes.

In testimony whereof I alfix my signature.

FREDERICK WILLIAM GUFFE.

